Process for the manufacture of aluminium nitrid.



APPLIUATION FILED MAY], 1912.

Patented Apr. 29, 1913.

' m'messss INVENTOK cam; sra'rs rarer rare ,OTTOKAR SER-PEK, OF PARIS, FRANCE, ASSIGNOR TO SOCIETE GENEBALE.DES NITRURES, OF PARIS, FRANCE.

PROCESS FOR THE MANUFACTURE OF ALUMINIUM NITRID.

Specification of Letters Patent.

Patented Apr. 29, 191 3.

Application filed May 7, 1912. Serial No. 695,723.

Process for the Manufacture of Aluminium Nitrid, of which the following is a specification. I

It is known that aluminium nitrid is mans ufactured by heating alumina (or substances containing it) mixed with carbon in a current of nitrogen. But although revolving furnaces have given very good results working on a large scale, it appears that it would be advantageous in working on a small scale to be able to carry out the manufacture of the -nitrid in stationary furnaces the construction of which demands little expense.

The .bbje'ct of the present invention is a recess allowing of carrying out this manuacture of the nitrid equally well in stationary furnaces. For this purpose, there is employed an electrical resistance furnace, the resistance being brought to the desired terplperature by an electric current.

itrogen is supplied to the substances heated in such a manner that there are formed cavities around the electrode during the reaction. This result is obtained either by directly introducing nitrogen through the e ectrical resistance and allowing it to escape at'the points where it is more particularly desired to obtain the cavities, or by passing transversely of the mass tubes leading to the immediate neighborhood of the resistance in order to allow the nitrogen to escape at this point. Owing to this arrangement, agglomeration of the nitrid against the resistance is avoided. Since the latter is a very good insulator of heat, without this precaution the radiating effect of the resistance would decrease rapidly to a large extent. This cavity presents moreover the great. advantage of allowing the introduction of fresh material. This fresh material introduced arrives in this way directly in the hottest zone which is itself protected externally against losses of heat by the thicl r layer of nitrid formedfso that-the conversion into nitrid of the mixture introduced takes place very rapidly. This method of workingincreases considerably the efficiency of the 0poration in the electrical furnace, not only as regards the absolute quantity of nitrid produced per operation, but also as regards the weight of nitrogen fixed per kilowatthour.

By way of example, there is shown in vertical section in the annexed drawing a furnace allowing the carrying out of this process.

The furnace A is vertical. At the center,

a heatin resistance B is arranged between mixture E is converted into aluminium nitrid. Tubes G G allow of recharging into the furnace at certain'quantity of the mix.-

ture. I

Instead of using tubes G for recharging the furnace at the top, there may be arranged openings H upon its periphery. After having removed the plugs H closing the openings, the unagglomeratedv mixture E obstructing them is removed, the crust- E mice heating, said process consisting insupname to this specification, in the presence of 1'i{lgf11i%0g811 in the iminefliiatfi niiighbortwo subscribing Witnesses.

00c 0 t e resistance ant t ere y orming i a cavity between the resistance and the ni- OTTOKAR SERPEK' 5 trid produced and supplying the mixture to said cavity.

In testimony whereof, I have. signed my Witnesses:

H. 0. Com,

LEON PEILLET.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,-

Washington, I). 0. 

